Non-bleeding iron test paper that has been developed as a simple and quick method to detect iron (II) ions in hydrophylic substrates. These ions are harmful to organic substrates, such as paper, because they catalyse the oxidative degradation of cellulose and other organic materials.
The test paper is non-bleeding, therefore it can be applied to originals. The test paper has been extensively tested in paper conservation. In general a positive reaction of the iron (II) test is a distinct identification of the presence of an iron-gall ink. However, it has to be realised that other inks and colourants, e.g. bistre, may be iron based or contaminated with iron.
Iron (II) ions are water soluble and will migrate into a dampened test paper in contact with the ink. The indicator (bathophenanthroline) forms an intensely red-coloured complex with iron (ii) ions.
Instructions are provided with the test papers.